In a filament winding process, fiber strands are impregnated with resin and subsequently wound on a shaped support which may be a mandrel or a base element (liner), e. g. a plastic vessel. Once the winding operation is completed and the resin is cured, the shaped support is either removed from the wound package or it remains in place and becomes part of the wound package. Normally, winding is realized according to a predetermined pattern which is executed by means of a CNC control unit. The fiber strands generally consist of a plurality of filaments, e. g. of 1,000 to 12,000 fine fibers which are gathered into rovings, i. e. fiber bundles, or into tapes and flat bands, respectively, having a titer of 1,000 tex and more.
Before the production of a wound package is started, a fiber strand is positioned on the mandrel or the base element, respectively. After winding, the fibers must be cut and made as even with the surface of the product as possible. Up to now, the fibers have been manually stuck on the mandrel or the liner prior to the start of manufacture. They have also been manually cut and made even with the surface of the wound package after completion of the winding operation. Cutting is necessary to allow for the release of the completed wound package from the installation and its delivery. To allow a fiber strand (roving or flat band) to be wound on the next form, it has to be linked with that new base element.
It is a known procedure following the production of a wound package to wind a fiber strand from the latter onto an intermediate carrier in form of an adjacent tube. The fibers of the strand are fixed on said tube, and the fibers which connect it with the mandrel are cut by means of a blade. After the removal of the completed wound mandrel and the insertion of a new, non-wound mandrel, the fibers of the intermediate carrier are wound onto the mandrel. However, there is the disadvantage that the usual cutting and binding technique does not allow for a fully automated production using the filament winding process.
To wind tennis racket frames, a portal machine with a lathe has been used whose central spindle drive actuates a mandrel supported in a jewelled bearing on the left and right sides each. A fiber strand from a spool creel each is guided through an associated impregnation bath to a traversing arm. The portal is provided with a travelling drive alternately actuating one traversing arm and then the other to allow the respective fiber strand to be wound on one mandrel or the other. Once the winding operation on the first mandrel is terminated, the fiber strand is wound along the mandrel and brought into a parking position proximate to the spindle box. The controlled drive releases the current traversing arm and travels to the other side to actuate the second traversing arm. The result is an accumulation of wound roving ends in the respective parking position—which requires manual interventions to avoid long stops—and consequently the premature hardening of the resin, with the manual interventions impeding in turn a continuous operation. The expenditures for mechanical equipment are considerable because all components except the main drive and the common drive for the traversing arms are required in duplicates.